// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/renderer/pepper/pepper_platform_audio_output.h"

#include "base/bind.h"
#include "base/location.h"
#include "base/logging.h"
#include "base/single_thread_task_runner.h"
#include "base/threading/thread_task_runner_handle.h"
#include "build/build_config.h"
#include "content/child/child_process.h"
#include "content/common/media/audio_messages.h"
#include "content/renderer/media/audio_message_filter.h"
#include "content/renderer/pepper/audio_helper.h"
#include "content/renderer/render_thread_impl.h"
#include "ppapi/shared_impl/ppb_audio_config_shared.h"

namespace content {

// static
PepperPlatformAudioOutput* PepperPlatformAudioOutput::Create(
    int sample_rate,
    int frames_per_buffer,
    int source_render_frame_id,
    AudioHelper* client)
{
    scoped_refptr<PepperPlatformAudioOutput> audio_output(
        new PepperPlatformAudioOutput());
    if (audio_output->Initialize(sample_rate,
            frames_per_buffer,
            source_render_frame_id,
            client)) {
        // Balanced by Release invoked in
        // PepperPlatformAudioOutput::ShutDownOnIOThread().
        audio_output->AddRef();
        return audio_output.get();
    }
    return NULL;
}

bool PepperPlatformAudioOutput::StartPlayback()
{
    if (ipc_) {
        io_task_runner_->PostTask(
            FROM_HERE,
            base::Bind(&PepperPlatformAudioOutput::StartPlaybackOnIOThread, this));
        return true;
    }
    return false;
}

bool PepperPlatformAudioOutput::StopPlayback()
{
    if (ipc_) {
        io_task_runner_->PostTask(
            FROM_HERE,
            base::Bind(&PepperPlatformAudioOutput::StopPlaybackOnIOThread, this));
        return true;
    }
    return false;
}

bool PepperPlatformAudioOutput::SetVolume(double volume)
{
    if (ipc_) {
        io_task_runner_->PostTask(
            FROM_HERE,
            base::Bind(&PepperPlatformAudioOutput::SetVolumeOnIOThread,
                this, volume));
        return true;
    }
    return false;
}

void PepperPlatformAudioOutput::ShutDown()
{
    // Called on the main thread to stop all audio callbacks. We must only change
    // the client on the main thread, and the delegates from the I/O thread.
    client_ = NULL;
    io_task_runner_->PostTask(
        FROM_HERE,
        base::Bind(&PepperPlatformAudioOutput::ShutDownOnIOThread, this));
}

void PepperPlatformAudioOutput::OnError() { }

void PepperPlatformAudioOutput::OnDeviceAuthorized(
    media::OutputDeviceStatus device_status,
    const media::AudioParameters& output_params,
    const std::string& matched_device_id)
{
    NOTREACHED();
}

void PepperPlatformAudioOutput::OnStreamCreated(
    base::SharedMemoryHandle handle,
    base::SyncSocket::Handle socket_handle,
    int length)
{
#if defined(OS_WIN)
    DCHECK(handle.IsValid());
    DCHECK(socket_handle);
#else
    DCHECK(base::SharedMemory::IsHandleValid(handle));
    DCHECK_NE(-1, socket_handle);
#endif
    DCHECK(length);

    if (base::ThreadTaskRunnerHandle::Get().get() == main_task_runner_.get()) {
        // Must dereference the client only on the main thread. Shutdown may have
        // occurred while the request was in-flight, so we need to NULL check.
        if (client_)
            client_->StreamCreated(handle, length, socket_handle);
    } else {
        main_task_runner_->PostTask(
            FROM_HERE, base::Bind(&PepperPlatformAudioOutput::OnStreamCreated, this, handle, socket_handle, length));
    }
}

void PepperPlatformAudioOutput::OnIPCClosed() { ipc_.reset(); }

PepperPlatformAudioOutput::~PepperPlatformAudioOutput()
{
    // Make sure we have been shut down. Warning: this will usually happen on
    // the I/O thread!
    DCHECK(!ipc_);
    DCHECK(!client_);
}

PepperPlatformAudioOutput::PepperPlatformAudioOutput()
    : client_(NULL)
    , main_task_runner_(base::ThreadTaskRunnerHandle::Get())
    , io_task_runner_(ChildProcess::current()->io_task_runner())
{
}

bool PepperPlatformAudioOutput::Initialize(int sample_rate,
    int frames_per_buffer,
    int source_render_frame_id,
    AudioHelper* client)
{
    DCHECK(client);
    client_ = client;

    RenderThreadImpl* const render_thread = RenderThreadImpl::current();
    ipc_ = render_thread->audio_message_filter()->CreateAudioOutputIPC(
        source_render_frame_id);
    CHECK(ipc_);

    media::AudioParameters params(media::AudioParameters::AUDIO_PCM_LOW_LATENCY,
        media::CHANNEL_LAYOUT_STEREO,
        sample_rate,
        ppapi::kBitsPerAudioOutputSample,
        frames_per_buffer);

    io_task_runner_->PostTask(
        FROM_HERE, base::Bind(&PepperPlatformAudioOutput::InitializeOnIOThread, this, params));
    return true;
}

void PepperPlatformAudioOutput::InitializeOnIOThread(
    const media::AudioParameters& params)
{
    DCHECK(io_task_runner_->BelongsToCurrentThread());
    if (ipc_)
        ipc_->CreateStream(this, params);
}

void PepperPlatformAudioOutput::StartPlaybackOnIOThread()
{
    DCHECK(io_task_runner_->BelongsToCurrentThread());
    if (ipc_)
        ipc_->PlayStream();
}

void PepperPlatformAudioOutput::SetVolumeOnIOThread(double volume)
{
    DCHECK(io_task_runner_->BelongsToCurrentThread());
    if (ipc_)
        ipc_->SetVolume(volume);
}

void PepperPlatformAudioOutput::StopPlaybackOnIOThread()
{
    DCHECK(io_task_runner_->BelongsToCurrentThread());
    if (ipc_)
        ipc_->PauseStream();
}

void PepperPlatformAudioOutput::ShutDownOnIOThread()
{
    DCHECK(io_task_runner_->BelongsToCurrentThread());

    // Make sure we don't call shutdown more than once.
    if (!ipc_)
        return;

    ipc_->CloseStream();
    ipc_.reset();

    Release(); // Release for the delegate, balances out the reference taken in
        // PepperPlatformAudioOutput::Create.
}

} // namespace content
